1. Field of the Invention
The present invention relates to an ultrasonic vibration cutting tool and to a production method thereof.
2. Description of the Prior Art
A cutting tool making use of ultrasonic vibration is described at page 218 of xe2x80x9cUltrasonicsxe2x80x9d published by Corona Co., Ltd. in Jun. 30, 1999.
Ultrasonic vibration cutting tools are divided into two types: an integrated type in which a blade projecting outward from the peripheral surface of a resonator is integrated with the resonator and a separate type in which a disk-like blade is attached to a resonator. Since the blade and the resonator are made from the same material in the case of the integrated type, when the blade is formed from a material best suited for a member to be cut, the material of the resonator may not have excellent acoustic characteristics, or when the resonator is formed from a material having excellent acoustic. characteristics, the material of the blade has poor compatibility with the member to be cut. Therefore, the material of the blade is limited inevitably. In the case of the separate type, the blade and the resonator can be formed from different materials. For example, the blade is formed from a material best suited for a member to be cut and the resonator is formed from a material having excellent acoustic characteristics. However, since the blade is attached to the resonator, the transmission efficiency of ultrasonic vibration from the resonator to the blade becomes worse inevitably compared with the integrated type.
Then, the present invention provides an ultrasonic vibration rotary cutting tool which can optimize materials as in a separate type and, can improve the transmission efficiency of ultrasonic vibration as in an integrated type, as well as a production method thereof.
According to an aspect of the present invention, there is provided an ultrasonic vibration cutting tool comprising a ring-shaped projection and a blade essentially composed of diamond and held by the ring-shaped projection, all of which are formed on the peripheral surface of a vibration. conversion portion provided on a resonator, wherein the outer diameter of the blade is made larger than the outer diameter of the ring-shaped projection. According to this invention, the blade is formed from a material best suited for a member to be cut regardless of the resonator and integrated with the resonator. Therefore, the optimization of materials as in the separate type and the improvement of the transmission efficiency of ultrasonic vibration as in the separate type can be made possible.
According to another aspect of the present invention, there is provided a method of producing an ultrasonic vibration cutting tool, the method comprising the steps of immersing a resonator having a vibration conversion portion and a ring-shaped projection in a plating solution obtaining diamond powders and growing a blade essentially composed of diamond with the ring-shaped projection as a seed by electroplating. According to this invention, an ultrasonic vibration cutting tool which can optimize materials as in the separate type and can improve the transmission efficiency of ultrasonic vibration as in the integrated type can be easily produced.
In the above invention, if the peripheral portion of the ring-shaped projection is removed after the growth of the blade so that the ring-shaped projection is located inside the peripheral portion of the blade, the outer diameter of the blade can be set properly.
The above and other objects, advantages and features of the present invention will become more apparent from the following description when taken into conjunction with the accompanying drawings.